Dwight Howard's knee will affect him for a short while he recuperates. Athletes are always getting injuries and they get the best healthcare so they will be able to get back to peak form in no time. Dwight Howard is a very valuable player and cannot be held back very long.
When Dwight Howard was injured in the last game the general consensus was that this would be a death blow to the outcome of game 3 and ultimately, the entire series. Howard is a talented franchise player and the knee injury will have a minor impact to game 3. It does not look though that it will completely affect the series.
There is a whole lot of running and jumping in basketball. This can be hard on a good knee can you imagine having to do it on a bad knee. Anyway, despite this Howard still put out a great game and his injury certainly didn't seem to effect it one bit. In the end his team only lost by one point.
With Dwight Howard being injured, he will have to play differently if he plays at all in game 2. If he plays, of course his aggression in the game will have to be taken down a notch in order to avoid further injury in the game. He may choose to rest his knee in game 2 of the series so he could be better in games 3 and further out.